1. Field of the Invention
The present invention relates to image processing apparatuses and methods and programs. More specifically, the present invention relates to an image processing apparatus and method and program that serve to recognize an object more accurately.
2. Description of the Related Art
Recently, devices (techniques) for recognizing persons have been developed and are being used. For example, it has been proposed to use techniques for recognizing persons to improve security by checking whether a person entering a certain place is allowed (has a permission) to enter the place. Also, it has been proposed to provide information in accordance with preference of a person recognized using the recognition techniques.
In the techniques for recognizing a person, an image of the face of the person is captured, and matching between the image of the face and a face image registered in advance is checked (the degree of similarity is calculated), thereby executing recognition to determine whether the person is a registered person. When a person is recognized in the manner described above, matching between a face image registered in advance and a face image that is obtained is checked. At this time, the direction of the face in the face image registered in advance and the direction of the face in the face image that is not obtained are not necessarily the same.
In some cases, matching between face images captured from different directions is to be checked, for example, when the face image registered in advance is a face image captured from the front and the face image that is obtained is a face image captured at an oblique angle of 45 degrees. It has been proposed to use a standard three-dimensional model of a human face when matching between face images captured from different directions is to be checked (i.e., when a face captured from a direction different from the direction of the registered face is to be recognized), for example, as described in Japanese Unexamined Patent Application Publication No. 2000-322577.
According to Japanese Unexamined Patent Application Publication No. 2000-322577, it is proposed that, in order to compare two face images captured from different directions, one of the face images is attached (mapped) to a three-dimensional face model to synthesize a face image captured from a direction corresponding to the direction of the other face image, thereby generating face images with the same direction from the face images with different directions to allow face (person) recognition.
Also, according to Volker Blanz et al., “Face Recognition Based on Fitting a 3D Morphable Model”, IEEE Transactions on Pattern Analysis and Machine Intelligence, Vol. 25, No. 9, September 2003, it has been proposed to transform a standard three-dimensional face model using various parameters to synthesize face images and to execute face recognition using parameters associated with a face image most approximate to an input face image.